1. Field of the Invention
A conventionally configured snap-in bushing used to retain a center seal O-ring in proper location has a circular, ring-like configuration. Upon insertion of such a conventionally configured bushing into position, enabling it to both support a brake actuator push rod or the like and retain the O-ring seal, radial fingers on the bushing snap into a groove in an adapter base to secure the bushing, and the seal retained by the bushing, in place. Effectiveness of the bushing in guiding and minimizing tilting of the push rod throughout its stroke is compromised, however, since the fingers have to be flexible enough to permit insertion of the bushing into a seal opening in the adapter base. Parking spring breakage, to which incomplete bushing insertion can contribute, is the most common reason for spring brake failure.
2. Description of Related Art
U.S. Patent Application Publication 2007/0034465 to Thompson et al. discloses a bushing assembly for an actuator center seal with at least six flexible tabs. The tabs flex to absorb side loading while maintaining a bushing position within the actuator assembly.
U.S. Pat. No. 5,272,933 to Collier et al. shows a damping ring for a rack and pinion steering gear. Flexible inner fingers of the damping ring resist transfer of vibration to the steering wheel.
U.S. Pat. No. 5,709,283 to Nief discloses a rack and pinion power steering gear with a seal retainer. The seal retainer includes a flexible portion to hold the seal against an inner portion of the shaft, but lacks solid portions to absorb side loading.
U.S. Pat. No. 5,829,339 to Smith shows a sealed bushing assembly for a brake actuator. A thermoplastic bushing is placed in a sleeve secured to a steel adaptor base. The sleeve retains the bushing, and the sealed bushing maintains the seal between the actuator chambers.